The present invention relates to methods for controlling combustion in a multicylinder controlled temperature combustion engine using gasoline-like fuel, particularly in a homogeneous charge, compression ignition (HCCI) type engine, also known as a premixed charge compression ignition (PCCI) engine.
Various prior art publications recognize that several parameters influence the initiation of combustion in an HCCI engine. See, for example, U.S. Pat. No. 6,286,482 to Flynn, et al., and Aceves, HCCI Combustion: Analysis and Experiments, SAE 2001-01-2077. Such recognized parameters include: fuel type, compression ratio, intake charge temperature, oxygen concentration in the charge air, equivalence ratio, charge air density, and boost pressure. However, absent from the prior art is a practical method for controlling the initiation of combustion in an HCCI engine to the optimum timing (e.g., as determined by crank angle location) over the full range of an engine's speed and load operation. Also absent from the prior art is a practical method for successfully transitioning from one speed/load operating point to another speed/load operating point quickly (i.e., controlling transient engine operation). Also, absent from the prior art is a practical method for adjusting (or balancing) the combustion from cylinder to cylinder in a multicylinder engine during engine transients (which requires very fast adjustment, e.g., within a single engine cycle or less than 1/30 of a second at high engine speed). The present invention provides a new method of operation for an engine with HCCI combustion that eliminates these and other deficiencies of the prior art.